Hi,
I just saw your post. It's probably too late but I'll post as reference: MFCreateSinkWriterFromURL() needs to be passed both the file path (or at least the file extension) and the bytestream.
Here is a C++ code sample creating an MP4 video with a bouncing square:
#define _USE_MATH_DEFINES
#include <cmath>
#include <wrl\client.h>
#include <ppltasks.h>
#include <mfapi.h>
#include <mfidl.h>
#include <mfreadwrite.h>
#include "MediaWriter.h"
using namespace Microsoft::WRL;
using namespace concurrency;
using namespace Extensions;
using namespace Platform;
using namespace Windows::Foundation;
using namespace Windows::UI::Core;
#define CHK(statement) {HRESULT _hr = (statement); if (FAILED(_hr)) { throw ref new COMException(_hr); };}
// Class to start and shutdown Media Foundation
class AutoMF
{
public:
AutoMF()
: _bInitialized(false)
{
CHK(MFStartup(MF_VERSION));
}
~AutoMF()
{
if (_bInitialized)
{
(void) MFShutdown();
}
}
private:
bool _bInitialized;
};
Windows::Foundation::IAsyncActionWithProgress<double>^ MediaWriter::WriteAsync(Windows::Storage::Streams::IRandomAccessStream^ stream)
{
return create_async([this, stream]
(progress_reporter<double> reporter, cancellation_token token) {
// some parameters
const unsigned int WIDTH = 640;
const unsigned int HEIGHT = 480;
const unsigned int RATE_NUM = 30000;
const unsigned int RATE_DENOM = 1000;
const unsigned int BITRATE = 3000000;
const unsigned int ASPECT_NUM = 1;
const unsigned int ASPECT_DENOM = 1;
const unsigned long BPP_IN = 32;
const long long hnsSampleDuration = 10000000 * (long long)RATE_DENOM / (long long)RATE_NUM;
const unsigned long cbMaxLength = WIDTH * HEIGHT * BPP_IN / 8;
const unsigned int ONE_SECOND = RATE_NUM / RATE_DENOM;
const unsigned int FRAME_NUM = 10 * ONE_SECOND;
AutoMF mf;
//
// Create the Sink Writer
//
ComPtr<IMFByteStream> spByteStream;
CHK(MFCreateMFByteStreamOnStreamEx((IUnknown*)stream, &spByteStream));
ComPtr<IMFAttributes> spAttr;
CHK(MFCreateAttributes(&spAttr, 10));
CHK(spAttr->SetUINT32(MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS, true));
ComPtr<IMFSinkWriter> spSinkWriter;
CHK(MFCreateSinkWriterFromURL(L".mp4", spByteStream.Get(), spAttr.Get(), &spSinkWriter));
//
// Setup the output media type
//
ComPtr<IMFMediaType> spTypeOut;
CHK(MFCreateMediaType(&spTypeOut));
CHK(spTypeOut->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Video));
CHK(spTypeOut->SetGUID(MF_MT_SUBTYPE, MFVideoFormat_H264));
CHK(spTypeOut->SetUINT32(MF_MT_AVG_BITRATE, BITRATE));
CHK(spTypeOut->SetUINT32(MF_MT_INTERLACE_MODE, MFVideoInterlace_Progressive));
CHK(MFSetAttributeSize(spTypeOut.Get(), MF_MT_FRAME_SIZE, WIDTH, HEIGHT));
CHK(MFSetAttributeRatio(spTypeOut.Get(), MF_MT_FRAME_RATE, RATE_NUM, RATE_DENOM));
CHK(MFSetAttributeRatio(spTypeOut.Get(), MF_MT_PIXEL_ASPECT_RATIO, ASPECT_NUM, ASPECT_DENOM));
DWORD streamIndex;
CHK(spSinkWriter->AddStream(spTypeOut.Get(), &streamIndex));
//
// Setup the input media type
//
ComPtr<IMFMediaType> spTypeIn;
CHK(MFCreateMediaType(&spTypeIn));
CHK(spTypeIn->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Video));
CHK(spTypeIn->SetGUID(MF_MT_SUBTYPE, MFVideoFormat_RGB32));
CHK(spTypeIn->SetUINT32(MF_MT_INTERLACE_MODE, MFVideoInterlace_Progressive));
CHK(MFSetAttributeSize(spTypeIn.Get(), MF_MT_FRAME_SIZE, WIDTH, HEIGHT) );
CHK(MFSetAttributeRatio(spTypeIn.Get(), MF_MT_FRAME_RATE, RATE_NUM, RATE_DENOM));
CHK(MFSetAttributeRatio(spTypeIn.Get(), MF_MT_PIXEL_ASPECT_RATIO, ASPECT_NUM, ASPECT_DENOM));
CHK(spSinkWriter->SetInputMediaType(streamIndex, spTypeIn.Get(), nullptr));
//
// Write some data
//
CHK(spSinkWriter->BeginWriting());
double progress = 0.;
LONGLONG hnsSampleTime = 0;
for (unsigned int nFrame = 0; nFrame < FRAME_NUM; nFrame++)
{
if (token.is_canceled())
{
break;
}
double newProgress = 100. * (double)nFrame / (double)FRAME_NUM;
if (newProgress - progress >= 1.)
{
progress = newProgress;
reporter.report(progress);
}
//
// Create a media sample
//
ComPtr<IMFSample> spSample;
CHK(MFCreateSample(&spSample));
CHK(spSample->SetSampleDuration(hnsSampleDuration));
CHK(spSample->SetSampleTime(hnsSampleTime));
hnsSampleTime += hnsSampleDuration;
//
// Add a media buffer filled with random data
//
ComPtr<IMFMediaBuffer> spBuffer;
CHK(MFCreateMemoryBuffer(cbMaxLength, &spBuffer));
CHK(spBuffer->SetCurrentLength(cbMaxLength));
CHK(spSample->AddBuffer(spBuffer.Get()));
// Draw a bouncing white rectangle over black background
unsigned char *pbBuffer = nullptr;
CHK(spBuffer->Lock(&pbBuffer, nullptr, nullptr));
for (unsigned int i=0; i < HEIGHT; i++)
{
for (unsigned int j=0; j < WIDTH; j++)
{
unsigned int pos = 4 * (i * WIDTH + j);
unsigned char val = 255 * (
(abs((int)WIDTH / 2 - (int)j) < (WIDTH / 4)) &&
(abs(HEIGHT * (.5 + .1 * sin(2. * M_PI * (double)nFrame / (double)ONE_SECOND)) - (int)i) < (HEIGHT / 4))
);
pbBuffer[pos ] = val;
pbBuffer[pos+1] = val;
pbBuffer[pos+2] = val;
pbBuffer[pos+3] = val;
}
}
CHK(spBuffer->Unlock());
//
// Write the media sample
//
CHK(spSinkWriter->WriteSample(streamIndex, spSample.Get()));
}
if (!token.is_canceled())
{
CHK(spSinkWriter->Finalize());
reporter.report(100.);
}
});
}
and a JavaScript code sample calling it:
var stream = null;
Windows.Storage.KnownFolders.videosLibrary.createFileAsync("out.mp4", Windows.Storage.CreationCollisionOption.generateUniqueName).then(function (file) {
if (file) {
file.openAsync(Windows.Storage.FileAccessMode.readWrite).then(function (newStream) {
stream = newStream;
var writer = new Extensions.MediaWriter();
return writer.writeAsync(stream);
}).then(function () {
stream.close();
stream = null;
var player = document.getElementById('player');
player.src = URL.createObjectURL(file, { oneTimeOnly: true });
player.play();
}, function (error) {
stream.close();
stream = null;
}, function (progress) {
document.getElementById('progressbar').value = progress;
});
}
});
